West Nile Virus for Providers

Reporting

• Suspected and confirmed cases of West Nile virus (WNV) infection are reportable. Reports may be made by:
  • Fax: 714-564-4050
  • Phone: 714-834-8180
  • E-mail: epi@ochca.com

 

Clinical Diagnosis

• West Nile virus (WNV) disease should be considered in any person with a febrile or acute neurologic illness who has had recent exposure to mosquitoes, blood transfusion, or organ transplantation, especially during the summer months in areas where virus activity has been reported. The diagnosis should also be considered any infant born to a mother infected with WNV during pregnancy or while breastfeeding.

Laboratory Diagnosis

• Serum or cerebral spinal fluid (CSF) should be collected for WNV-specific IgM. Commercial assays are widely available to do this testing. We no longer recommend confirmation by plaque neuralization assay (PNA).
  • IgM should be detectable 3-8 days after onset of symptoms and should remain for 30-90 days.
  • Negative IgM testing done prior to 8 days after onset of symptoms should be repeated.
• County and State Public Health Laboratories (PHL) do not provide routine viral culture or nucleic acid amplification testing (NAAT) for WNV.

Treatment

• There are no specific treatments for West Nile Virus.